OMG, I just mounted a real, physical System 7 "InstallMeFirst" floppy disk inserted in a standard USB floppy disk drive in the macOS 27 Finder — complete with classic icons! This was possible using my (in development) Disk Phoenix application via FSKit. Disk Phoenix recreates the classic Mac HFS (and MFS) file system, and is picked up as a "supported" file system. I can also Quick View the TeachText file, and Get Information on the system file 
(Note: the icon drawing is still flakey, which I think is a macOS bug. Watch this space.)
(Note: the icon drawing is still flakey, which I think is a macOS bug. Watch this space.)